From: Avi Kivity <avi@qumranet.com>
To: qemu-devel@nongnu.org
Cc: linux-mips@linux-mips.org
Subject: Re: [Qemu-devel] QEMU/MIPS & dyntick kernel
Date: Tue, 02 Oct 2007 22:27:07 +0200 [thread overview]
Message-ID: <4702A99B.7020008@qumranet.com> (raw)
In-Reply-To: <20071002200644.GA19140@hall.aurel32.net>
Aurelien Jarno wrote:
> Hi,
>
> As announced by Ralf Baechle, dyntick is now available on MIPS. I gave a
> try on QEMU/MIPS, and unfortunately it doesn't work correctly.
>
> In some cases the kernel schedules an event very near in the future,
> which means the timer is scheduled a few cycles only from its current
> value. Unfortunately under QEMU, the timer runs too fast compared to the
> speed at which instructions are execution.
Sounds like a kernel bug. Can't there conceivably exist real hardware
(or a real timeout) that exhibits the same timing?
Especially today with variable clock frequencies, I don't see how the
kernel can rely on exact timing.
--
Any sufficiently difficult bug is indistinguishable from a feature.
next prev parent reply other threads:[~2007-10-02 20:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-02 20:06 QEMU/MIPS & dyntick kernel Aurelien Jarno
2007-10-02 20:06 ` [Qemu-devel] " Aurelien Jarno
2007-10-02 20:27 ` Avi Kivity [this message]
2007-10-02 20:37 ` Aurelien Jarno
2007-10-02 20:48 ` Alan Cox
2007-10-02 20:48 ` Alan Cox
2007-10-02 20:57 ` Aurelien Jarno
2007-10-02 20:57 ` Aurelien Jarno
2007-10-02 22:35 ` Ralf Baechle
2007-10-02 22:35 ` Ralf Baechle
2007-10-04 1:59 ` J. Mayer
2007-10-04 16:19 ` Daniel Jacobowitz
2007-10-15 1:23 ` Paul Brook
2007-10-15 8:15 ` Dor Laor
2007-10-15 15:05 ` Thiemo Seufer
2007-10-15 15:58 ` Ralf Baechle
2007-10-15 15:58 ` Ralf Baechle
2007-10-15 16:20 ` Thiemo Seufer
2007-10-15 16:20 ` Thiemo Seufer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4702A99B.7020008@qumranet.com \
--to=avi@qumranet.com \
--cc=linux-mips@linux-mips.org \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.